Hiroshi Miyazato

Adjustable speed control of ultrasonic motors by adaptive control

The driving principle of the ultrasonic motor (USM) is different from those of the electro-magnetic type motors. Some mathematical models for the USM have been reported; however, these models are very complex to apply for speed control of the USM. Therefore, the speed controllers have been designed using PI controllers or fuzzy controllers and it is necessary to develop a simple and convenient mathematical model for the USM in order to achieve a high-performance speed control. In this paper, a mathematical model for the USM is proposed which is simple and useful for speed control. The speed controller is designed based on the model using adaptive control theory. Adaptive control is attractive for control of the USM because the speed characteristics of the USM vary with drive conditions. The application of this control scheme to speed control for the USM is attempted first. The effectiveness of proposed control is demonstrated by experimental. >

Granular cell tumor of the rectum: a case report and review of the literature.

Abstract: A 47-year-old Japanese woman with a 5-year history of alcoholism was admitted to the Ryukyu University Hospital for the treatment of the alcoholism. For evaluation of observed changes in her bowel habits, she underwent colonoscopy, which revealed seven small polyps spread throughout the entire large intestine. Six of the polyps were in the colon; one was an adenoma and five were hyperplastic polyps. The remaining polyp, in the rectum, was an 8-mm submucosal tumor. Pathological analysis of a biopsy of the lesion in the rectum indicated a possible diagnosis of adenocarcinoma. Endoscopic ultrasonography (EUS) demonstrated a submucosal hypoechoic nodule, involving the mucosa and the muscularis propria. Subsequently, the patient underwent a radical low anterior resection of rectum. The lesion was a submucosal tumor with ulceration. The tumor consisted of granular tumor cells which were positive for S-100 protein, neuron-specific enolase, and periodic acid schiff (PAS) stain, but negative for desmin and vimentin. Granular cell tumor is rare in the gastrointestinal tract. As a result, such tumors can be misinterpreted to indicate a possible malignancy on either a biopsy or EUS.

Increased rate of P300 latency prolongation with age in drug-naive and first episode schizophrenia

OBJECTIVE Previous studies have found an increased rate of P300 latency prolongation with age in medicated chronic patients with schizophrenia, suggesting a pathological neurodegenerative process. In this study, we investigated whether this abnormality was identified in drug-naive and first episode patients with schizophrenia. METHODS P300 from auditory stimuli was recorded from 20 drug naive and first episode male patients with schizophrenia and compared with 23 age and handedness matched healthy male controls. The relationship of P300 latency and P300 amplitude to age in each group was evaluated using polynomial regression analyses. RESULTS Reduction of P300 amplitude was significant in drug-naive and first episode schizophrenia patients. P300 amplitude negatively correlated with age in schizophrenia patients but not in controls. Although the prolongation of P300 latency with age was observed in both groups, the regression slope for P300 latency with age was significantly steeper in patients with schizophrenia than in normal controls. Significant overall curvilinear correlations with age were also found for P300 latency and amplitude in patients with schizophrenia, and for P300 latency in normal controls. CONCLUSIONS The greater increase in P300 latency and reduction in P300 amplitude with age may be a primary neuropathological effect of schizophrenia. SIGNIFICANCE This study suggests that neurodegenerative processes are involved in the etiology of schizophrenia.

Radiation-Associated Rectal Cancer: Report of Four Cases

Background/Aims: Radiation-associated rectal cancer is a remarkable clinical entity. We demonstrate 4 patients (mean age 68 years, range 63–74) who had undergone pelvic radiotherapy for cervical cancer. We indicate some characteristics of radiation-associated rectal cancer. Results: Two patients had received intracavitary and external pelvic radiotherapy, while the remaining 2 had external pelvic radiotherapy following hysterectomy. The mean total radiation dose was 63 Gy, though radiation dose information was not available for 1 patient. Colorectal cancer developed at a mean time of 20.7 years (range 11–30) after radiation therapy. All patients presented with chronic radiation colitis, and 3 demonstrated abnormal tumor markers. Colonoscopy revealed an ulcerative, localized well-differentiated adenocarcinoma of the rectosigmoid colon in 1 patient, and diffusely infiltrating cancers of the lower rectum, one signet-ring cell carcinoma and two mucinous carcinomas in the remaining 3. One case was stage I, 2 were stage IIIa, and the remaining case was stage IV. Three patients underwent abdominoperineal resection. The remaining patient was felt to be inoperable. The colorectal wall demonstrated the changes of chronic radiation injury. Two patients died within a short time because of their advanced cancers. Conclusion: Radiation-associated rectal cancer has a tendency to be diagnosed in the advanced stage and to have a poor prognosis. A literature review and our case report suggest that since there are no reliable clinical or laboratory indicators of the presence of a curable colorectal cancer in the setting of chronic radiation proctocolitis, surveillance with a colonoscope should be done 10 years after irradiation in patients with previous pelvic radiotherapy.

Abnormalities of auditory P300 cortical current density in patients with schizophrenia using high density recording.

While P300 current density analysis has been performed in schizophrenic patients, the event-related potential data have never been obtained using a high density recording, nor have their cortical images been well demonstrated. In this study, the auditory P300 elicited by an oddball paradigm was recorded using a high density recording system of 128 channels. Thirteen male patients who met DSM-IV criteria for schizophrenia were compared with 20 healthy male controls. The cortical current density analysis of low resolution electromagnetic tomography (LORETA) was applied to the P300 component, and this resulted in the values of 6222 current density points over the surface of a cortex model. The inter-group difference of P300 current density was assessed using a point-by-point comparison by t-test. While the normal controls demonstrated the cortical activation of bilateral frontal, temporal and parietal cortex during the oddball paradigm, visual inspection suggested that in the schizophrenic patients these areas were less activated. The inter-group significance of P300 current density was dominant over the left hemisphere, and particularly over the left prefrontal area. It is concluded that the LORETA current density analysis localizes the neural activity from the cortical fronto-temporo-parietal network as the neural substrates of the scalp recorded P300. The dysfunction of such a network, especially over the left hemisphere, possibly subserves the scalp recorded P300 abnormality in schizophrenia.

Cholinergic modulation of the sleep state-dependent P13 midlatency auditory evoked potential in the rat

Injections into the pedunculopontine nucleus (PPN) of the cholinergic receptor agonist, carbachol (CAR), were found to reduce the amplitude of the vertex-recorded, sleep state-dependent P13 midlatency evoked potential in a dose- and time-dependent manner. This effect was blocked or reduced by pretreatment with the muscarinic receptor antagonist, scopolamine, injected into the PPN.

The N200 abnormalities of auditory event-related potentials in patients with panic disorder.

Cognitive impairment in patients with panic disorder (PD) has been studied using event-related potentials (ERPs). However, previous studies obtained ERP data only at a few scalp sites, and seldom investigated N200 measurements from the difference waveforms. In the present study, auditory ERPs were recorded at 16 scalp sites during an active discrimination task of oddball paradigm. Fourteen PD patients (8 with agoraphobia; 6 without agoraphobia) were compared with 14 sex- and age-matched control subjects. For the nontarget waveforms, P2 amplitude was reduced in PD patients. For the target waveforms, a topographical difference between female PD patients and female controls was found for N200 amplitude, which attenuated in female PD patients over the parietal area. Two subcomponents of N200, N2a and N2b, were measured from the difference waveforms. A significant group difference was found for N2b amplitude, which reduced in PD patients compared with unaffected control subjects. It is suggested that N2b reduction reflects an abnormally controlled processing of stimulus information in PD.

Quick and precise position control of ultrasonic motors with two control inputs

The ultrasonic motor (USM) has an excellent performance and many useful features. Since this motor is superior in holding torque and high response characteristic, it has been expected to be used as a position servomotor for small motors. The driving principle of an ultrasonic motor is, however, different from those of electromagnetic type motors and its mathematical model has not been developed yet. Moreover, its speed characteristics vary with driving conditions. Therefore, it is difficult to control ultrasonic motor with high performance. This paper presents a new position control scheme of an ultrasonic motor, which controls both driving frequency and phase difference, to achieve a quick and precise position control. This control scheme consists of a PI controller and an adaptive controller, which compensates the speed characteristic variations. The effectiveness of this control scheme is demonstrated by experiments.<<ETX>>

Analyses of Microsatellite Instability and the Transforming Growth Factor-β Receptor Type II Gene Mutation in Sporadic Human Gastrointestinal Cancer

Microsatellite instability (MSI) and transforming growth factor-beta receptor type II (RII) gene mutation have been reported in many types of tumors and their instance seem to vary among the tumors investigated. To determine the relation between MSI and RII gene mutation in sporadic gastrointestinal cancer development, 21 esophageal, 19 gastric, and 27 colorectal cancers were investigated. The presence of MSI was screened by single strand conformation polymorphism (SSCP) method using six microsatellite markers. RII gene mutations were detected by SSCP method and direct sequencing. MSI was detected in seven of 21 (33.3%) esophageal cancers, three of 19 (15.8%) gastric cancers and seven of 27 (25.9%) colorectal cancers. However, RII gene mutations were observed in only two of seven (28.6%) MSI-positive colorectal cancers. Our data suggest that among sporadic gastrointestinal cancers, colorectal cancers seem to be the most frequent target organ involved in carcinogenesis through RII gene mutation, which thus appears to be related to organ specificity.

Morphologic and mucin histochemical analysis of transitional zones in advanced ulcerated colorectal carcinomas : Potential prognostic indicators

Background and Objectives: The transitional zone, which is normal‐appearing mucosa that surrounds a primary colorectal carcinoma, has characteristic histologic features, and an increased amount of sialomucin in the transitional zone have been associated with a poorer prognosis. To clarify the prognostic effects of changes in the transitional zone we studied the transitional zone in cancers of the colon and rectum.