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We designed and fabricated a low-aberration miniature column with electrostatic lenses. It includes two octupole aligners for optical adjustment, and two objective lenses, one for main focusing and the other for low-magnification observation. The optical characteristics of the objective lenses were calculated with Munro’s program. We obtained values of 2.9 mm for the chromatic aberration coefficient and 14 mm for the spherical aberration coefficient, at a working distance of 2 mm. We also developed a compact concentric sputter ion pump with a TFE e-gun. The pumping speed is 6 l/sec, and the end pressure is 10−7 Pa. By using this miniature column and the TFE e-gun assembly, we developed a compact scanning electron microscope. We achieved 10-nm resolution at 1.3-keV landing energy.

To test whether the posterior external auditory canal (EAC) wall reconstructed only by soft tissues retracts after surgery in the noninflamed ear.The condition of the posterior EAC wall was observed for more than 1 year after surgery in 20 noninflamed ears in which only the posterior EAC wall skin was preserved or in which the wall was reconstructed only by soft tissue during surgery.Eighteen patients (20 ears) underwent ear surgery for conditions other than otitis media, including ossiculoplasty in 12 ears, cochlear implant in 3, resection of congenital cholesteatoma in 4, and resection of glomus tympanicum tumor in 1.Retraction of the soft posterior EAC wall was observed in only 1 of the 20 ears. In this ear, the posterior EAC wall showed only a slight retraction without any serious problems. Computed tomography revealed that mastoid aeration recovered in all 20 ears.In noninflamed ears, surgeons can remove the bony posterior EAC wall if necessary, and may not need to reinforce or reconstruct the wall with hard tissue. This enables surgeons to spare time and energy and obtain the same advantages as in the intact-canal-wall technique or canal wall reconstruction by a hard material.

To determine the relationship between preservation of the mastoid mucosa during ear surgery and retraction of the attic or posterior wall of the external auditory canal (EAC) and mastoid aeration after surgery.Retraction of the posterior EAC wall and mastoid aeration were evaluated after surgery in 48 individuals (50 ears) with cholesteatoma, adhesive otitis media, or chronic suppurative otitis media, in whom the posterior bony EAC walls were removed with or without preservation of mucosa and reconstructed with soft tissues alone (EAC skin and temporal fascia) during surgery.Postoperative computed tomography showed that in ears with notable retraction of the posterior EAC wall appearing like an open mastoid cavity, there was no air in the mastoid, whereas in ears with no or only slight retraction there was computed tomographic evidence of mastoid aeration. Second, notable retraction of the posterior EAC wall occurred in a significantly smaller percentage of ears in which at least the epitympanic mucosa had been able to be preserved during surgery than in those that had undergone removal of all mucosa (mastoidectomy).These results indicate that 1) preservation of epitympanic mucosa during surgery is an important factor for prevention of retraction of the posterior EAC wall and for reaeration of the mastoid after surgery, and 2) the intact canal wall technique seems to be indicated whenever at least the epitympanic mucosa can be preserved, and when no mucosa can be preserved the canal wall down procedure seems to be indicated.

A simple and low-cost eye monitoring system with infrared illumination was developed. This system consists of a small board mounted with an infrared sensitive CCD camera and its control unit and a swimming goggle; it is light-weight and visualizes eye movements by connecting the output lines of the board to the video input on a monitor. We have found the present system useful in the routine vestibular clinic practice.

Effect of adenoidectomy on sinusitis was investigated in 78 children (aged 5 to 7) with adenoid vegetation, sinusitis and otitis media with effusion. After a 6 month period, improvement of the sinusitis was observed in 25 of the 45 children (56%) in the adenoidectomized group, and only in 8 of the 33 children (24%) in the non-adenoidectomized group. This was statistically significant in the adenoidectomized group (mean 2 = 7.65, p.01). Through nasopharyngeal endoscopy in the adenoidectomized children in the 6 months following surgery, we noted decreased evidence of infection and/or inflammation. These findings may indicate that adenoidectomy is effective for sinusitis in children.

We developed a miniature, high-brightness electron beam system that employs silicon micro field emitters (Si-MFEs) as an electron beam source. Si-MFEs are promising not only for reducing the size of electron guns, but also for increasing their brightness by two or three orders of magnitude compared to that of conventional electron guns. This is possible because they can reduce the electron optical aberrations by about a thousand times. We evaluated the characteristics of single Si-MFE from the perspective of the electron gun. Our micro electron gun was fabricated by ultra high vacuum (UHV) compatible processes and, for the first time, we succeeded in obtaining the SEM images using electrons emitted from Si-MFE.

To estimate the usefulness of magnetic resonance imaging (MRI) in diagnosing vertebro-basilar insufficiency (VBI), 41 VBI patients with vertigo or dizziness and 26 subjects without vertigo or dizziness (as control) were examined by MRI. Sixty-eight percent of the VBI group and 12% of the control group showed a large difference between the right and the left vertebral artery diameter, the incidence being significantly higher in the VBI group. Thirty-nine percent of the VBI group and 12% of the control group had lacunar infarction in the brain stem, of which the incidence was significantly higher in the VBI group, MRI can be recommended to diagnose VBI providing information on both blood vessel disorder and ischemic changes in the brain.

Parasagittal surface coil magnetic resonance imaging (MRI) of the internal auditory canal and the inner ear was performed in patients with otoneurological diseases. T2-weighted fast spin-echo sequences, plain and enhanced T1-weighted sequences were used to examine the inner ear and the individual nerves in the internal auditory canal. Normal parasagittal images of the inner ear and the internal auditory canal and 4 patients with otoneurological disorders are presented. Precise location of the acoustic tumor was visualized and postoperative status of the internal auditory canal and the inner ear was assessed by the present method. The cochlear nerve was not identified in a patient with long-standing unilateral deafness. A follow-up study with MRI was performed in a patient with Meniere's disease who underwent endolymphatic-mastoid shunt surgery, showing gradual postoperative shrinkage of the shunted endolymphatic sac. The present method provides a new approach to the assessment of otoneurological disorders.

An auditory-evoked magnetic field was recorded before and during tinnitus remission induced by an intravenous lidocaine injection. One and 4 kHz probe tones were presented monaurally in four tinnitus patients, and the responses were recorded using a 122-channel magnetometer. Three normal volunteers were also examined as controls. In tinnitus patients, the N100 m peak became sharper, while there was no marked change except for slight reduction in amplitude in normal subjects. Tinnitus remission by lidocaine may be related to attenuation of a masking-like effect of tinnitus on the sound-evoked responses.

The large vestibular aqueduct (VA) has been known as one of the congenital anomalies causing sensorineural hearing loss (SNHL). The clincial picture of this disease is characterized by attacks of sudden hearing loss and vertigo, followed by a spontaneous recovery (hearing fluctuationd) as observed in some of the cases. The possibility of a large VA being, a direct cause of hearing loss and hearing fluctuation, however, is still controversial. To clarify the mechanism of their SNHL and hearing fluctuation in patients with large VA, we have already reported that the course of their hearing and ist correlation with the size of VA (Okumura et al. 1995). In this paper, we introduce computed tomography (CT) and magnetic resonance imaging (MRI) of the large VA and its correlation with clinical symptoms.

Three patients with prelingual deafness and six patients with postlingual deafness using multichannel cochlear implants were examined by positron emission tomography using 15O-labeled water. Changes in regional cerebral blood flow (rCBF) were measured during three different sound stimuli: 1) with no sound stimulation, with the speech processor of the cochlear implant system switched off, 2) hearing white noise, and 3) hearing sequential Japanese sentences. In postlingually deaf patients, speech stimulation caused a significantly greater rCBF increase compared with noise stimulation in the left immediate auditory association area and the bilateral auditory association areas. In these patients, speech sound is thought to be processed by means of auditory cortices analogous to those in normal subjects. In contrast, in prelingually deaf patients, speech sound induced much less rCBF increase in auditory association cortices; this finding suggested underdevelopment of the neural network for complex sound analysis and speech sound recognition.

Since 1987 we have implanted 60 severely hearing-impaired adults with the Nucleus Minisystem-22 cochlear implant. In most cases, the surgical procedures were performed with satisfactory results and very few postoperative problems. The complications associated with cochlear implant surgery include difficulty in drilling the ossified cochlea, electrode displacement, and insufficient insertion of the electrode. Postoperative problems include dizziness, tinnitus, facial nerve spasm, receiver-stimulator migration or extrusion, infection of the scalp flap, and facial nerve palsy. In most cases, these complaints did not develop into serious conditions.

Over the past 7 years we have implanted the Nucleus multichannel cochlear implant in 60 patients with severe hearing impairment. The postoperative speech recognition of adult postlingually deaf patients was satisfactory. Adult prelingually deaf patients exhibited poorer speech perception than postlingually deaf patients. However, some patients showed better results than expected. The prelingually deaf patients needed a longer rehabilitation period than the postlingually deaf patients. There was considerable variation in performance among the prelingually deaf patients. As for juvenile deaf patients, some showed good speech perception ability, but postoperative rehabilitation took longer. The cooperation of doctors, audiologists, speech therapists, schoolteachers, and family members was essential, and the creation of a cochlear implant center for children is desirable to obtain better rehabilitation. On the questionnaire given to the cochlear implant patients, some complained about their hearing in a noisy environment or while listening to television or music. The present cochlear implant system obviously needs further improvement.

Inflammatory factors appear to play an important role in the development of otitis media with effusion (OME). However, otitis media experimentally induced by endotoxin injection or secondary immunoresponse was not persistent. In order to produce refractory OME, two pathologic conditions were necessarily combined: tubal ventilatory dysfunction and suppression of the immunologic defense mechanism by immunosuppressive drugs. In the presence of these two pathologic conditions, all cases that evidenced negative middle ear pressure due to tubal dysfunction developed OME. In the control group with either tubal dysfunction or immunosuppression alone, only 1 of 20 ears developed OME. Transtubal infection due to negative middle ear pressure caused by tubal ventilatory dysfunction may be one of the most important etiologic factors in OME.

1. Oxidative phosphorylation and respiratory enzyme activities were measured in the mitochondria from the non-involved lobe of the liver in eighteen patients with massive tumour mainly localized to one lobe and from the regenerating livers of partially hepatectomized rats treated with chloramphenicol. 2. In patients, the concentrations of cytochrome a(+ a3) varied from 40 to 170 pmol/mg of protein. In mitochondria with cytochrome a(+ a3) concentrations more than 70 pmol/mg of protein, the phosphorylative activity per mg of mitochondrial protein was considerably higher than in controls. The mitochondrial oxidative and phosphorylative activities per unit of cytochrome a(+a3) were negatively correlated with the concentration of cytochrome a(+ a3). These patients with mitochondrial cytochrome a(+a3) exceeding 70 pmol/mg of protein tolerated partial hepatectomy well. On the other hand, in patients with mitochondrial cytochrome a(+ a3) less than 60 pmol/mg of protein, phosphorylative activity was very low and there was a high surgical mortality. 3. In the regenerating liver of rats treated with chloramphenicol, the oxidative and phosphorylative activities per unit of cytochrome a(+ a3) were negatively correlated with the concentration of cytochrome a(+a3). 4. It is suggested that an increase in ATP-synthesizing activity per unit of respiratory assemblies is the most basic homeostatic mechanism maintaining energy production in response to an increased metabolic load upon hepatic cells.

Therapeutic effect and the mechanism of the action of human urinary trypsin inhibitor (MTI) on experimental acute pancreatitis were studied. MTI significantly increased survival rate of animals with experimental acute pancreatitis induced by the infusion of trypsin or phospholipase A2 into pancreas or by a closed duodenal loop. The efficacy of MTI on these types of pancreatitis were higher than those of aprotinin. Pancreatic enzymes were released from pancreatic slice by trypsin or phospholipase A2, and this release was inhibited by MTI. Further, these pancreatic enzymes caused a secondary release of enzymes from other pancreatic slice, suggesting that these enzymes injured pancreatic tissue and that a chain reaction of pancreatic enzyme activation may play an important role in the pathogenesis of acute pancreatitis. MTI suppressed the secondary enzyme-induced pancreatic injury more strongly than aprotinin. These results suggest that MTI may suppress pathogenesis and development of pancreatitis by inhibiting the chain reaction of pancreatic enzyme activation.

The standard audiometric tests of hearing impairment were performed iii 62 school children of cerebral palsy and the following results were obtained.1) 17 of them had hearing impairment and 15 of them, 27 ears, showed perceptive deafness.2) Perceptive deafness was noted in 44 o of the children with athetoid form, 14.3% of the children with spastic form and none of the children with ataxic form.3) Generally, 7400 of these perceptive deaf children showed high tone deafness. Especially in the children with athetoid form. 16 of 18 ears were found to have the high tone deafness. There was no characteristic pattern in the audiogram of the children with spastic form.4) In 10 cases, the hearing loss in the audiogram was of the symmetric type.5) Generally, no marked relation was found between the occurence of hearing impairment and the etiological factors of the cerebral palsy.

In this study the experiences with carcinomas of the pancreas, ampulla of Vater, terminal comma bile duct, and duodenum found in a series of 3,610 patients collected from 57 major Japanese institutions was compiled over a 26 year period. The results were analyzed as to the success of resectional and palliative surgery for the various lesions. The most common lesion was carcinoma of the head of the pancreas. Unifortunately, only 18.3% of these patients were resectable with a 25.3% mortality. Carcinoma of the body and the tail was the second most frequent lesion, and it also exhibited a low resection rate. Carcinomas of the ampulla and the terminal common bile duct and duodenal regions were the most favorable for resection; usually pancreatoduodenectomy with an overall mortality of 20.8%. As a result of the large number of pancreatectomies performed, there was also a large number of postoperative complications, the most frequent being leakage at an anastomotic line. Hemorrhage also occurred frequently. Distal pancreatectomies were reserved for carcinoma of the body and the tail of the pancreas, and the most common postoperative complication of this procedure was hemorrhage. There were only 45 total pancreatectomies among the 973 resections being performed most frequently in patients with carcinoma of the head of the pancreas. Again, the most frequent postoperative complication was hemorrhage, followed by anastomotic leakage. The long term survivals following resection for these lesions were each poor. The best mean survival time was 22.7 months for carcinoma of the ampulla of Vater. Patients having resections for carcinoma of the head of the pancreas had a mean survival time of 12.3 months. At 5 years there were few survivors and most of them were patients who had undergone resections for carcinoma of the ampulla of Vater.

Therapeutic effects of human urinary trypsin inhibitor (MTI) on acute pancreatitis were examined. MTI potently inhibited not only proteases such as trypsin or alpha-chymotrypsin, but also inhibited lipase or creatine phosphokinase which are considered to be related to pancreatitis. Although gabexate mesilate (gabexate) and aprotinin also strongly inhibited trypsin, their inhibition spectra against pancreatic enzymes were narrower and aprotinin also strongly inhibited trypsin, their inhibition against pancreatic enzymes were narrower than MTI. MTI inhibited proteases released from pancreatic slice by trypsin more potently than gabexate or aprotinin. The therapeutic effects of MTI on experimental acute trypsin-induced pancreatitis in dogs or rats were stronger than those of gabexate or aprotinin. These results suggest that MTI may suppress pathogenesis and development of pancreatitis in several ways, for example, by directly inhibiting trypsin and by inhibiting tissue-damaging enzymes released from the pancreas by stimulation with trypsin.